JPH03143481A - Thread cutter for embroidering sewing machine - Google Patents

Abstract

PURPOSE:To enable upper thread to be cut off so that the upper thread left to be attached to the side of cloth may be extremely shortened in a state that lower thread is left without being cut off, by composing respective cutter elements movably toward upper thread pieces, and by setting a lower thread shunting means for shunting the lower thread outside the loci of movement of the cutting edges of the respective cutter elements. CONSTITUTION:When a needle 8 is vertically moved through a needle hole 2a and a shuttle 4 is rotationally moved and cloth 40 is horizontally moved by a cloth stretching frame 40a, then an upper thread piece 41 fed through the needle 8 is entwined with a lower thread piece 42 stored in the shuttle 4 and payed out of it, and sewing and embroidering are performed with the thread pieces. In this case, cutter elements 11, 12 in a thread cutting device 10, and a lower thread drawing piece 17 are in the state of preparation. After that, when the sewing comes to an end, then by a lower thread shunting means, the lower thread piece 42 is shunted outside the passing loci of the cutting edges of the cutter elements 11, 12. In other words, the lower thread shunting means is formed with the cloth stretching frame 40a, and by the horizontal movement of the cloth stretching frame 40a, namely, by movement in the direction for separating the lower thread piece 42 from the passing loci of the cutter elements 11, 12, the lower thread 42 is horizontally moved, and is shunted at a position out of the loci of pathes of the cutting edges of the respective cutter elements 11, 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thread cutting device for cutting sewing thread after sewing is completed in an embroidery sewing machine.

[Conventional technology]

This type of thread cutting device generally cuts the upper thread and lower thread together. Therefore, for example, when sewing while changing the needle thread color frequently, the bobbin thread is cut each time the color is changed, resulting in poor thread alignment at the beginning of sewing with the needle thread of each color, which can easily cause threads to fall out. There is a point. In order to solve this problem, the needle thread hook provided below the throat plate uses a hook to move the needle thread to a side location and away from the bobbin thread. There is a thread cutting device designed to cut the thread (for example, Japanese Patent Application Laid-Open No. 63-1155
(See Publication No. 92).

(Problems to be Solved by the Invention) In this conventional thread cutting device of an embroidery sewing machine, the thread is cut at positions that are unevenly distributed to the side, so there is a problem that the upper thread that remains attached to the fabric side after cutting is long. There is a point. There is a problem in that such a long needle thread requires a troublesome operation such as cutting with scissors in a subsequent process.

The present invention has been made in view of the above points, and its purpose is to be able to cut only the upper thread while leaving the bobbin thread uncut, and when cutting the upper thread, it is possible to cut only the upper thread while leaving the lower thread uncut. To provide a thread cutting device for an embroidery sewing machine capable of cutting a needle thread so that the needle thread remaining attached is extremely short.

[Means to solve problems]

In order to achieve the above object, the present invention takes the measures as described in the claims above, and its effects are as follows.

[Effect]

When cutting the upper thread, the lower thread is retracted out of the locus of movement of the multiple blades in the pair of cutter elements by the lower thread retracting means, and then the upper thread is cut at the same position by the cutter element. Therefore, the length of the needle thread remaining on the surface side is extremely short.

〔Example〕

The drawings showing the embodiments of the present application will be described below.

In FIG. 1, numerals 1 to 9 indicate the constituent members of a well-known multi-axis embroidery sewing machine (for example, the same as that shown in Japanese Patent Application Laid-Open No. 60-173156).
is a throat plate, 3 is a shaft for driving the hook, 4 is a hook, 5 is an arm disposed above the bed l, 6 is a holder attached to the arm 5 so as to be horizontally rotatable, 7 is a holder 6 A plurality of needle bars are provided so as to be able to move up and down relative to each other, and a plurality of needle bars are provided around the center of rotation of the holder 6. Reference numeral 8 indicates a needle provided on each needle bar 7, and reference numeral 9 indicates a presser foot. Reference numeral 10 indicates a thread cutting device provided below the needle vi2, and reference numeral 40a indicates a fabric frame (also called an embroidery frame) which is movable in the horizontal direction on the bed 1.
A drive device built into the bed 1 allows the bed to be driven in the above directions. A cloth 40 to be embroidered is stretched over the frame 40a.

Next, the thread cutting device 10 will be explained in detail based on FIG. 2.3. Reference numerals 11 and 12 designate a pair of cutter elements, which are pivotally attached to the lower surface side of the throat plate 2 using a pivot 13.

Each cutter element 11.12 has a respective blade 11a, 11b and 12a, 12b. 14 is a wave washer,
By pressing the cutter element 12 against the cutter element 11, the spring means is exemplified to improve the mutual rubbing of the blades in the double force vine element. 1
5.16 shows the driven piece attached to each cutter element, 1
Reference numeral 7 designates a lower thread pull-out piece disposed below the pair of cutter elements 11 and 12, which is formed integrally with the cutter element 12 in this example. The positional relationship between the needle hole 2a, each cutter element 11, 12, and the bobbin thread pull-out piece 17 is such that the locus of movement of each tip passes through approximately the middle position of the needle hole 2a, as shown in FIG. Next, reference numeral 21 indicates a drive mechanism in the thread cutting device 10. Reference numeral 22 indicates a base frame of the drive mechanism, which is also called a mounting base and is fixed to the bend l. Reference numeral 23 denotes a drive shaft rotatably mounted on the base frame 22, and a drive lever 24 is fixed to the upper end. The drive lever 24 is provided with engagement holes 25 and 26, which are illustrated as drive parts, and each of the driven pieces 15 and 26 is provided with engagement holes 25 and 26, respectively, which are illustrated as drive parts.
16 is engaged. As a result, the forward movement of the lever 24 moves each cutter element 11.12 toward a position below the needle hole 2a, so that the blades 11a and 12a move toward the needle hole 2a.
a, and each cutter element 11.12 also has a needle hole 2.
a, while the return movement of the lever 24 causes each cutter element 11.12 to move below the needle hole 2a towards the position of its blades 11b and 12b.
meet below the needle hole 2a, and each cutter element 11.12
moves past the lower position of the needle hole 2a. 27 is a transmission lever attached to the lower end of the drive shaft 23; 28 is a drive device for moving the transmission lever 27 in the direction of the arrow; for example, a solenoid is used (an air or hydraulic cylinder may also be used).

Next, numeral 31 shown in FIG. 2 is a needle thread distribution a structure, which is used to distribute the needle thread into the thread on the side connected to the cloth and the thread on the side connected to the needle 8. Reference numeral 32 denotes a mounting frame for the mechanism, which is fixed to the bed 1. Reference numeral 33 denotes a drive device attached to the mounting frame 32, for example, a rotary lenoid in which a drive shaft 33a rotates back and forth is used. Reference numeral 34 denotes an upper thread hanging piece, which is formed in a forked shape, and the base part is connected to the drive shaft 33a using a mounting bracket 35, so that it can be moved in and out of the hook 4.

Next, the operation when cutting the upper thread with the bobbin thread stuck in the thread cutting device 10 and left uncut will be explained based on the time chart in Fig. 5, the operation explanation in Figs. 6 to 8, and the clear drawings. explain. In addition, in these figures, Fig. 6 (A) and Fig. 7 (
A), Figure 8 (A) is a plan view, Figure 7 (B) is Figure 7 (
The vertical cross-sectional view of the cloth, throat plate, and thread cutting device taken at the B-8 position in A), FIG. 6(B), and FIG. 7(C) are B-B in FIG. 6.7(A), respectively. An enlarged longitudinal cross-sectional view showing the relationship between the needle hole 2a, the thread, and the force in the position, and the blade passage surface P in the ta element 11.12. FIG. 8(B) shows the thread and cutter in the state of FIG. 8(^) FIG. 3 is a horizontal cross-sectional view showing the relationship with elements. Also, Fig. 6 to Fig. 8 are indicated by the symbols ■ to ■ in Fig. 5, respectively.
This shows the state at each point in time.

In the process (a) in FIG. 5, as is well known, the needle 8 moves up and down through the needle hole 2a, the hook 4 rotates, and the cloth 40 is moved laterally by the fabric tensioning frame 40a, so that the needle As is well known, the upper thread 41 supplied through the needle thread 8 and the lower thread 42 stored in the hook 4 and fed out from the hook 4 are intertwined, and sewing and embroidery are performed using these threads. At this time, the cutter elements 11, 12 and the lower thread pull-out piece 17 in the thread cutting device 10 are 1! as shown in FIG. 6(A). In a state of readiness.

Next, when the above-mentioned sewing is completed, the lower thread 42 is retracted out of the 1ffi path of the blade of the cutter element 11.degree. 12 by the lower thread retracting means at the time point in FIG. 5(b). That is, in this example, the bobbin thread retracting means is constituted by the fabric upholstery frame 40a, and by moving the fabric upholstery frame 40a laterally, that is, moving the bobbin thread 42 away from the path of the cutter element 11.12, the bobbin thread is removed. 42 is laterally moved as shown in FIG. 6(B) and retracted to a position out of the path of the blade of each cutter element 1112 as shown in FIG.

Next, at the time point shown in FIG. 5(c), the cutter element 11.12 is moved forward from the state shown in FIG. 6(A) to the state shown in FIG. 7(A) by the operation of the drive mechanism 21. Next, at the time point in FIG. 5(d), the drive device 33 in the needle thread sorting machine fM31
is operated, and the upper thread folding piece 34 is moved as shown in FIG. 7(A).

It enters the pot 4 as shown in (B). In this state, the rotation of the hook 4 of the embroidery sewing machine and the vertical movement of the needle 8 are temporarily performed as shown in FIG. 5(E), and as shown in FIG. 7(A),
As shown in (B), the upper thread 41 is caught on the upper thread folded piece 34. In this state, as shown in FIG. 4, only the upper thread 41a on the right side remains within the path of the blade in the cutter element 11.12, and the needle thread 41b and lower thread 42 on the needle side have retreated outside the path of the blade. .

After the above state is reached, the drive Jl in the thread cutting device IO
j, the mechanism 21 is operated back and the cutter element 11.12 is moved in the return direction. During the movement process, each cutter element 11.12 moves towards the needle thread 41 located below the needle hole 2a, and the blades 11b, 12b therein move towards the upper thread 41 located below the needle hole 2a.
At the time of Figure 8(A), as shown in Figures 8(A) and 8(B), the upper thread 41 matches under the needle hole 2a and is attached to the cloth 40. Needle thread 41 on the continuous side
Cut a. In this case, since the needle thread 41a is cut below the needle hole 2a, the needle thread 41a° remaining on the cloth 40 side is extremely short (for example, 5 m). After the upper thread 41 is cut as described above, 41! The subsequently activated drive mechanism 21 returns the cutter element 11.12 to its ready position as shown in FIG. 6A. Further, the needle thread folded piece 34 is retracted out of the hook, and the fabric covering frame 40a is returned to the normal sewing position.

Next, the thread cutting device described above can also cut the bobbin thread 42. The operation is shown in the time chart in Figure 9 and in Figure 1.
This will be explained based on the operation explanatory diagram in Figure 0.11. After the sewing shown in FIG. 9 (A") is completed, the fabric covering frame 40 is
a is moved to the opposite side from the case described above, that is, moved in a direction that brings the bobbin thread 42 closer to the locus of movement of the cutter element 11.12, so that the bobbin thread 42 is moved laterally as shown in Figure 1 (B). However, as shown in FIG. 10(C), the blades of the cutter elements 11 and 12 are positioned in a mi-polar position within the locus of movement of the blades. In this state, the cutter elements 11.12 are moved forward by the drive mechanism 21, and the blades 11a, 12a are as shown in FIG. 11(A).
As shown in (B), the bobbin thread 42 is cut by matching below the needle hole 2a. Therefore, the lower thread 42 is connected to the cloth 40.
2a is cut very short.

In the case of an operation as described above, the blade I of the cutter element 11.12
Prior to the matching of La and 12a, the lower thread pull-out piece 17 is inserted into the needle hole 2.
a, and pull out the bobbin thread 42 from the hook 4. Therefore, among the lower threads 42, the lower thread 42b on the hook 4 side is relatively long (for example, 60 mm).

When cutting the upper thread after cutting the bobbin thread, as shown in Fig. 9 (2°), (N°), and (H),
=), (*), to C) is performed, and the needle thread is cut.

Next, FIGS. 12 and 13 show different embodiments of the present application, and show an example in which the bobbin thread retraction means is constructed by a hook 51. In FIG. It is pivoted to. 52 is a driving piece attached to the upper thread folding piece 34e, and 53 is a driven piece attached to the hook 51, which is provided so that the hook 51 operates in conjunction with the upper thread folding piece 34e. 54 indicates the hook 51 shown in imaginary lines in FIG. 13! A return spring 55 is a stopper at the ready position.

In such a bobbin thread retracting means, when the upper thread folded piece 34e enters the hook 4e, the hook 51 moves to the position shown by the solid line in FIG. 13, and the lower thread 42e is moved to the cutter element 11e.
, 12g. Note that the hook 51 may be provided with its own operating mechanism so that it can be operated independently.

It should be noted that parts that are considered to have the same or equivalent structure as those in the previous figure in terms of function are given the same reference numerals as in the previous figure with the letter e, and redundant explanations are omitted.

(Also, in the next and subsequent works, the same idea is used in the first ode, and the letters r, g, and h are added in order, and duplicate explanations are omitted.) Next, Figures 14 and 15 show the rubbing of a pair of cutter elements. This shows another example of a spring means for improving the condition, and shows an example in which a temporary spring 5G is used in place of the wave wansha.

Next, FIGS. 16 to 18 show a lid-side bobbin thread holding means for holding the cut bobbin thread on the side connected to the hook. The lid-side lower thread holding means 57 is constructed using a coil spring attached to a hook stopper, and when the lower thread 42g is pulled out by the lower thread pull-out piece 17g as shown in FIG. As shown in Figure 18, it is held between coil springs.

Next, FIGS. 19 to 21 show different embodiments of the lid-side lower thread holding means. In this example, the means 57h is the second
As shown in Fig. 1, a holding body 58 (referred to as a pile mat) in which a large number of flexible fiber bodies 58b are planted on a base cloth 58a is attached to the inner surface of a frame body 59, and this is attached to the throat plate. 2
It is attached to the bottom surface of h. According to the holding means, the second
When the lower thread 42h is pulled out by the lower thread pull-out piece 17h as shown in Fig. 0, the lower thread 42h is pushed into the holder 58 by the lower thread pull-out piece 17h as shown in Fig. 21, and is held in that state.

〔Effect of the invention〕

As described above, in the present invention, when sewing is completed, the cloth 40
When cutting the thread from the needle plate 2, a cutter element 11.
12 is a provision, it goes without saying that actuating the cutter elements 11 and 12 has the effect of cutting off the threads continuous under the cloth 40. In the above case, the lower thread retracting means 40a 42, there is only the upper thread 41 that descended with the needle 8 and remained after the needle 8 rose, so the upper thread 41
By moving the force lid element 11.12 toward
can be cut so that it becomes extremely short, which has the effect of making it unnecessary to organize the unnecessary upper thread 41a' hanging down from the cloth 40 in the subsequent process.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a vertical cross-sectional view of a main part of an embroidery sewing machine, FIG. 2 is a partially cutaway perspective view showing a thread cutting device provided in the bed of the embroidery sewing machine, and FIG. 4 is an exploded perspective view of the thread cutting device, FIG. 4 is a plan view showing the positional relationship between the needle hole and the locus of movement of the cutter element, FIG. 5 is a time chart, and FIG. 6 (^). (B), Figures 7 (A) to (C), Figure 8 (A), (
B) is an explanatory diagram of the operation, Fig. 9 is a time chart when cutting the bobbin thread, Figs. 10 (A) to (C), and Fig. 11 (
A) and (B) are explanatory views of the operation when cutting the bobbin thread, Fig. 12 is a perspective view showing different embodiments of the bobbin thread retracting means, Fig. 13 is a plan view of the same, and Fig. 14 is the thread cutting. 15 is a longitudinal sectional view showing the relationship between the cutter element and the spring in the example of FIG. 14; FIG. 16 is a plan view showing the lid-side bobbin thread holding means; FIG. , FIG. 17 is a vertical cross-sectional view of FIG. 16, FIG. 18 is a partially enlarged view showing the lower thread holding state, FIG. 19 is a vertical cross-sectional view showing different examples of the lid-side lower thread holding means, and FIG. 20. 19 is an explanatory view of the operation of the lid-side lower thread holding means in FIG. 19, and FIG. 21 is an enlarged vertical cross-sectional view showing the lower thread holding state by the lid-side lower thread holding means in FIG. 19. 2... Throat plate, 2a... Needle hole, 4... Hook, 11°1
2... Cutter element, 40a, 51... Lower thread retracting means, 40 - Cloth, 1 Upper thread, 42 Lower thread. Figure 7 (B) Figure (I3) Figure 0 (A) +1 Figure 10 CB) Figure 10 (0 Figure 11 (A) Figure 11 (B) Figure 14 Figure 15 Figure 16 Figure 9 Figure 20 Figure 21

Claims (1)

[Claims] A needle plate having a needle hole through which the needle moves up and down, and a hook located below the needle plate and storing the bobbin thread to be entwined with the needle thread that has descended with the needle through the needle hole. A thread cutting device for an embroidery sewing machine is provided with a pair of cutter elements arranged to cut the thread by matching their blades with each other, and each of the cutter elements moves toward the upper thread. A thread cutting device for an embroidery sewing machine, comprising a lower thread retracting means configured to freely move the lower thread, and retracting the lower thread out of the locus of movement of the blades of each of the cutter elements.